SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf2644fcded2c8af07accb457783445a8fa9f2cfd8f0339f5a441b2f53399c2' 
  AND token = 'miLVuaW9DIChrsjSp9DiOoHaWV0BiJQYNXq5lRdgofE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}